Antiprotozoal Compounds from Urolepis Hecatantha (Asteraceae)
Total Page：16
File Type：pdf, Size：1020Kb
Hindawi Evidence-Based Complementary and Alternative Medicine Volume 2021, Article ID 6622894, 7 pages https://doi.org/10.1155/2021/6622894 Research Article Antiprotozoal Compounds from Urolepis hecatantha (Asteraceae) Orlando G. Elso ,1,2 Maria Clavin ,1,2 Natalia Hernandez ,1 Toma´s Sgarlata ,1 Herna´n Bach ,3,4 Ce´sar A. N. Catalan ,5 Elena Aguilera ,6 Guzman Alvarez ,7 and Valeria P. Su¨lsen 1,2 1Universidad de Buenos Aires, Facultad de Farmacia y Bioqu´ımica, Ca´tedra de Farmacognosia, Jun´ın 956, Buenos Aires 1113, Argentina 2CONICET–Universidad de Buenos Aires, Instituto de Qu´ımica y Metabolismo del Fa´rmaco (IQUIMEFA), Jun´ın 956, Buenos Aires 1113, Argentina 3Universidad de Buenos Aires, Facultad de Farmacia y Bioqu´ımica, Museo de Farmacobot´anica, Jun´ın 956, Buenos Aires 1113, Argentina 4Instituto de Recursos Biol´ogicos INTA-Hurlingham, De los Reseros y N. Repetto (1686), Hurlingham, Buenos Aires, Argentina 5Universidad Nacional de Tucuma´n, Facultad de Bioqu´ımica Qu´ımica y Farmacia, Instituto de Qu´ımica Orga´nica, Ayacucho 471 (T4000INI), San Miguel de Tucuma´n, Argentina 6Grupo de Qu´ımica Medicinal-Laboratorio de Qu´ımica Org´anica, Facultad de Ciencias, Universidad de la Rep´ublica, Montevideo 11400, Uruguay 7Laboratorio de Mole´culas Bioactivas, Universidad de la Repu´blica, CENUR Litoral Norte, Paysandu´ 60000, Uruguay Correspondence should be addressed to Valeria P. S¨ulsen; vsulsen@ffyb.uba.ar Received 20 October 2020; Revised 1 February 2021; Accepted 3 February 2021; Published 12 February 2021 Academic Editor: Shagufta Perveen Copyright © 2021 Orlando G. Elso et al. *is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. *e dewaxed dichloromethane extract of Urolepis hecatantha and the compounds isolated from it were tested for their in vitro activity on Trypanosoma cruzi epimastigotes and Leishmania infantum promastigotes. *e extract of U. hecatantha showed activity against both parasites with IC50 values of 7 µg/mL and 31 µg/mL, respectively. Fractionation of the dichloromethane extract led to the isolation of euparin, jaceidin, santhemoidin C, and eucannabinolide. *e sesquiterpene lactones eucannabinolide and santhemoidin C were active on T. cruzi with IC50 values of 10 ± 2 µM (4.2 µg/mL) and 18 ± 3 µM (7.6 µg/mL), respectively. Euparin and santhemoidin C were the most active on L. infantum with IC50 values of 18 ± 4 µM (3.9 µg/mL) and 19 ± 4 µM (8.0 µg/ mL), respectively. Eucannabinolide has also shown drug-like pharmacokinetic and toxicity properties. 1. Introduction attributed to this parasitosis [2]. Chagas’ disease was his- torically linked to poor rural areas of Latin America where Chagas’ disease and leishmaniasis are protozoan parasitic the insect vector is present. In recent years, the disease has diseases caused by Trypanosoma cruzi and different species spread to cities and nonendemic areas due to migrations of of the genus Leishmania and transmitted by infected blood- infected people and nonvectorial transmission of the par- sucking triatomine bugs and phlebotomine sandflies, re- asite, turning Chagas’ disease into a global public health spectively. *ey are both classified as neglected tropical problem [3]. Nifurtimox and benznidazole are the only diseases by the World Health Organization (WHO) [1]. drugs currently available for Chagas’ disease treatment. Both Chagas’ disease or American Trypanosomiasis is a po- drugs are effective in the acute stage of the infection and tentially life-threatening disease that affects 6 to 7 million vertical transmission prevention, but their efficacy dimin- people worldwide. It is estimated that about 30000 new cases ishes in the chronic phase. Besides, frequent adverse events occur annually and more than 12000 deaths per year are lead to high rates of treatment discontinuation [4]. 2 Evidence-Based Complementary and Alternative Medicine *erefore, the development of new trypanocidal drugs for dichloromethane (3 × 60 mL). Dichloromethane subextracts Chagas’ disease treatment is needed. were joined and taken to dryness on a rotary evaporator to Leishmaniasis has three clinical forms: cutaneous, mu- yield 15 g of dewaxed extract. Dewaxed extract (DDE) was cocutaneous, and visceral also known as kala-azar. Although fractionated by silica gel column chromatography cutaneous leishmaniasis is the most common form, visceral (60 × 5 cm, 220 g, 230–400 mesh) and eluted with a gradient leishmaniasis is the most severe form [5]. According to the of dichloromethane (CH2Cl2) and increasing amounts of WHO, more than one billion people are at risk of infection. ethyl acetate (EtOAc): 100% CH2Cl2, CH2Cl2: EtOAc (9 :1), It is estimated that 30000 new cases of visceral leishmaniasis (8 : 2), (7 : 3), (6 : 4), (5 : 5), (4 : 6), (3 : 7), (2 : 8), (1 : 9), and and more than one million new cases of cutaneous leish- 100% EtOAc. Fractions (5 × 200 mL) of each solvent ratio maniasis occur annually [5]. *e chemotherapy of leish- (A1−5 to K1−5) were collected. All column chromatography maniasis is based on the use of sodium stibogluconate, fractions were monitored by thin-layer chromatography meglumine antimoniate, pentamidine, amphotericin B, using silica gel 60 F254 plates and anisaldehyde sulphuric as paromomycin, and miltefosine. *ese drugs are toxic and spraying reagent. have other limitations such as the route of administration, length and cost of treatment, and emergence of drug re- sistance [6]. 2.3. Compounds Isolation. Fractions A5 (100% DCM) and Natural products play an important role in the drug B1−5 (DCM: EtOAc 9: 1) were pooled and the solvent was discovery process. One of the most relevant examples is evaporated on a rotary evaporator. *e residue obtained was artemisinin, a sesquiterpene lactone isolated from Artemisia transferred to a small vial with a minimum amount of ethyl annua currently used for malaria treatment [7]. Several acetate and the solution was left at room temperature natural products with promissory activity against patho- overnight. From this solution, yellow acicular crystals of genic protozoa have been reported [8, 9]. compound 1 (euparin, 28 mg) were obtained. Urolepis hecatantha (DC) R. M. King and H. Rob. (syn. Fractions D2−5, eluted with CH2Cl2 : EtOAc (7 : 3), Eupatorium hecatanthum (DC) Baker) is the only species of and the fraction E1, eluted with CH2Cl2 : EtOAc (6 : 4), the monotypic genus Urolepis (Asteraceae) [10]. *e eth- showing a similar profile on TLC, were reunited and nomedical uses of the aerial parts of U. hecatantha by in- brought to dryness on a rotary evaporator. *e residue digenous groups of northeast Argentina have been reported was suspended in a minimum amount of dichloro- [11–13]. *e fresh aerial parts are chewed as antitussive [11], methane and purified by preparative TLC using silica gel while the infusion or decoction of the aerial parts is used plates. *e plates were developed using toluene: EtOAc : topically for gangrene and ulceration treatment [12]. *is formic acid (6 : 4 :1) as a mobile phase. After drying, species has been employed also as an analgesic for teeth pain plates were analyzed under UV light where a deep green treatment [13]. *e isolation of flavonoids, terpenoids, and fluorescent band (Rf � 0.6) was observed. *e fluorescent benzofuran derivatives from a collection of U. hecatantha band was scraped out and extracted with methanol. After from Bolivia has been reported [14]. solvent evaporation, a yellow powder (10 mg) identified In this work, we report the isolation of four compounds as jaceidin was obtained. from U. hecatantha from Argentina and the evaluation of Fractions H2-4, eluted with CH2Cl2 : EtOAc (3 : 7), their in vitro activity on Trypanosoma cruzi and Leishmania were pooled and concentrated under vacuum in a rotary infantum. *e toxicity and pharmacokinetic properties of evaporator. *e residue was dissolved with a minimum the compounds were also estimated. amount of ethyl acetate and allowed to stand at room temperature for 24 hours. From this solution, pure 2. Materials and Methods crystals of compound 3 (santhemoidin C, 120 mg) were obtained. Fractions I3-5, eluted with CH2Cl2 : EtOAc (2 : 2.1. Plant Materials. *e aerial parts of U. hecatantha (DC.) 8), and fractions J1-3, eluted with CH2Cl2 : EtOAc (1 : 9), R. King and H. Robins (Asteraceae) were collected in Buenos were combined and brought to dryness on a rotary Aires province, Argentina, in March 2018. *e plant material evaporator. *e residue was fractionated by silica gel was identified and deposited at the Herbarium of the Faculty column chromatography (50 × 3 cm, 150 g, 230–400 mesh) of Pharmacy and Biochemistry, University of Buenos Aires and eluted isocratically with a 2 :1 mixture of CH2Cl2 : (BAF 16100). EtOAc. Twenty fractions of 50 mL each were collected. Fractions 15–17 were reunited and brought to dryness on a rotary evaporator to afford compound 4 (eucannabi- 2.2. Extraction and Fractionation Procedures. Grounded nolide, 108 mg) as a colourless gum. Both 1H- and 13C- dried flowers and leaves of U. hecatantha (300 g) were NMR data of santhemoidin C (3) in DMSO-d6 as a solvent extracted thrice at room temperature with dichloromethane are reported here: δ 169.9 (C-1’’; acetate carbonyl), 169.0 (4.5 L, 6 h). Filtrates were joined and concentrated on a (C-12), 164.5 (C-1′), 150.2 (C-3′), 144.2 (C-4), 136.9 (C- rotary evaporator at 40°C under reduced pressure to give 11), 133.5 (C-10), 129.1 (C-1), 125.2 (C-2′), 123.0 (C-5), 42 g of crude extract (DE). *e crude extract was suspended 120.7 (C-13), 76.6 (C-3), 75.0 (C-6), 72.6 (C-8), 57.7 in ethanol (147 mL) at 60°C, diluted with distilled water (C-4′), 57.5 (C-5′), 50.8 (C-7), 42.8 (C-9), 35.4 (C-2), 20.2 (63 mL), and filtered under vacuum.